Saturday, November 14, 2009

Project 37

Coming to the end of the section on colour, this project was one I have been looking forward to.  It is many years since I have shot in Black and White and must admit to being very much attracted to colour and not really having any need to remove it from my images.  However, having a chance to explore a new medium using coloured filters would be fun.  I obtained a Cokin B&W filter kit with Red, Green, and Yellow filters, to which I added a Blue.

The trick now was going to be to take these images with a modern digital camera and avoid the camera re-balancing the colour back to a "nominal" normal.  Underwater I use red filters as red light is almost completely absorbed by 10m of water.  Adding a red filter and white balancing the camera on a grey card, reduces the influence of the other colours, bringing red back into the image, but at the cost of a couple of stops.  In this exercise I would need to do the opposite.

I set up the still life in a small light tent using a couple of strip lights from IKEA as my light sources, one to the right and one directly above to create some soft shadow.  I then photographed a grey card illuminated by the lights and used this image to establish a manual white balance, which I then used for all proceeding shots.

Here is the first photograph of the arrangement as a colour image, with my grey card as a reference.  In the following images I have done no post processing at all other than a conversion from RAW to JPG and reduction in size to 1024 points wide.  The camera was set on aperture priority at f/16 and ISO 100.  I also used a 50mm prime to avoid any creep in the focal length which would have happened on a zoom lens as I swapped out the filters.  In each photo I have simply indicated the length of the exposure.

Colour, 2 seconds

The next shot I took was exactly the same, but with the camera now switched to monochrome (actually this had to be done in Lightroom, as RAW does not care about B&W versus Colour).

No Filter, 2 seconds

In the next image I have added the blue filter to the lens

Blue, 8 seconds

With the blue filter the first change that is apparent is that we have lost 2 stops of light.  Other than that the blue background has lightened as have the green objects.  Moving onto the Green filter

Green, 15 seconds

With Green the light loss is now 3 stops and the Red items have darkened perceptibly, whilst the Green items are much lighter.  Next Red!

Red, 15 seconds

Once again a 3 stop loss of light, but this time a dramatic change in the colours, the Red peppers and tomatoes are almost white. What is also noticeable is that the Yellow objects show less colour change, but that might be because in monochrome they start as a very light shade of grey.  My final filter is Yellow

Yellow, 3 seconds

Only a 1/2 stop change in exposure an overall reduction in contrast, but no dramatic changes as seen with the red filter.

Very interesting exercise and perhaps a glimmer of interest in black and white, especially with the use of filters.

Project 36

Now that autumn has finally passed and winter is starting to make its presence felt, warm colours are starting to recede under continually grey skies.  However, on those days when the cloud clears the blue sky makes a great backdrop for photographing the architecture of the city.  The older buildings in Munich typically have 1 of two kinds of roof, terracotta tiles or sheet copper, turned green with age.  Imaging either of these against a blue sky and using a long telephoto makes for great contrast based photos.

First the  warm-cold contrast of the orange tiling against the sky

In the following image I had a high vantage point and so was able to shoot down and capture the reflection of the sky in the glass roof of the Stadtsparkasse Bank, a modern building inserted into an older frame:

On a similar theme the following two photographs superimpose the copper roof of a church spire and a copper coated statue against the sky, creating a combination of cool colours

In both images I have gone for a fairly punchy blue (I like colour), a more muted blue would have emphasized cold better.  For the warm images I moved indoors and shot some photos in Munichs cathedral, the first of candle light reflected on a bronze fitting, the second spot lights shining on a crucifix and illuminating the red brick behind

Assignment 2: Market

The Viktualienmarkt in the center of Munich offers many opportunities for colour combinations, with stalls selling fruit & vegetables, flowers, meat & poultry, and decorative items.  On the whole German supermarkets do not seel the wide variety of produce that English ones do, there is no equivalent to an out of town Sainsbury's or Tesco.  This means that if you want more unusual produce you must go to the market.

The main difficulty for a photographer is that the market is very busy on the weekends and the stall holders get quite fed up with people taking pictures and not buying anything.  I am starting to get used to getting dirty looks and even rude comments as I walk around with a camera, this is not limited to the market.  I guess I need to develop a thicker skin.

My first visit was on a Saturday morning and it proved difficult to get the images I wanted.  I took a day off work this week and found a quieter market coupled with much more tolerant stall holders.  The following images were made with a variety of telephoto primes, the new Canon 100mm IS, 200mm, and 300mm.  In practice I found that the longer focal lengths worked best as they allowed me to stand off and avoid interfering with the business of the stalls.  The drawback is that this means using natural lighting and thus a very shallow depth of field plus frequently having to raise the ISO quite significantly.

Complementary Colours

Similar Colours

Contrasting Colours

Colour Accent


From this set of images I have worked up a few ideas for quartets.  The first selection is in landscape format

The weakest image in this set  is the artichoke and radishes, the colour saturation is very different from the other shots and does not combine very well.  In this case I am using Red-Yellow for the contrast and Red-Green for the harmonious, with the green stalks on the tomatoes providing the colour accent. An alternate set with similar subjects is the following in Portrait

Following is a variation on the same theme

The final quartet is my current choice, the colours balance across the images although perhaps it would work better with the tomatoes from the second quartet as the accent rather than the chilli's which are not very well focused.

Friday, November 13, 2009

Project 35

Commencing with Red and Green, the richest location for finding combinations proved to be the city market, a location rapidly becoming my favorite for sourcing good subject matter.  The following image balances the red and green chilli peppers in 4 separate groups but delivers a close to 50:50 split of colour

In the next image the proportion is not quite so well balanced, however, the green stalks still attached to the tomatoes spreads the green colour across the image as does the green basket, although the blue basket containing the cucumbers clashes and reduces the purity of the image.

The final image with a red green balance is a staged still life detail shot.  Here the green is very pale, almost yellow, and I have made no attempt to balance the frame to a 50:50 ratio between the colours.

Finding subjects with an Orange:Blue combination was simple at this time of year, orange leaves against the blue sky proving an almost irresistible colour combination:

This image is not in the pure combination of 1:2, more likely 1:5, but is a good example of the harmony these two colours seem to create.  A more accurate 1:2 split can be obtained superimposing the terracotta roofing slates typical of Munich against a bright blue sky.  The following image follows rules of thirds almost exactly in the 1:2 split

This image is, however, rather dull, the next two images use the same basic subject matter for more interesting effect.  The first is a roof/sky combination shot through a church window

The second places the roofs in the context of the cityscape

This was shot from the top of the Alte Peter church's spire, a great vantage point to take panoramic shots of Munich, but only on a clear day.  It is also quite a walk up very narrow and sometimes rickety steps, quite safe, but not for the nervous minded.

Finding yellow and violet subject matter was difficult, violet is simply a rare colour, both naturally and artificially.  Once again my two images come from the market, where I was able to find a couple o0f good subjects, although I am quite loosely interpreting the colour violet.

These two images also use colour quite differently, the first use large blocks of colour, whilst in the second the yellow is present in small splashes in the straws and wooden blocks.

My final image returns to Orange:Blue and is a reversal of the suggested proportions, with the orange dominating, however, I still find this to be harmonious.

Project 34

For this project I used 3 sheets of  felt I have purchased to use as backdrops for still life work, fortunately in Black, White, and Grey.  For lighting I used simple overhead lighting in my work room.  The following composite has 15 shots each made half a stop apart:

Black - Top Row
In this sequence I have started at the camera suggested optimal exposure and then progressively underexposed by 1/2 stop.  Even at 2 stops underexposed the black is still reading at an RGB of (50,50,50), so still a very dark grey.  I suspect that the surface of the felt is slightly reflective and so would need at least another stop of under exposure to get a pure black. I noticed this when taking shots around town of black objects, most are very shiny surfaces and so although the hue is technically black so much light is reflected that it is nearly impossible to get an accurate black, without using the lens cap.

White - Middle Row
Here I have started again at a nominal ideal exposure, but opened up by 1.2 a stop in each successive image.  Even at two stops over the white is still quite grey (227,227,227).

Grey - Bottom Row
The final sequence is bracketed around the ideal exposure, so from -1 to 1 in half stop increments.  In this case the middle image at the "ideal" exposure is closest to where it should be at (120,120,120).  The grey I used was slightly paler than my reference grey card, so the proper image is probably the next one up.

What is also clear from the 3 separate images is that the camera has taken each of the different shades and rendered them to a neutral grey, all of the "ideal" shades are within 15/255 apart on the RGB scale.

I also shot image of all 3 shades together for comparison, this time setting an accurate exposure with a grey card.  It is quite striking how different the shades of grey are, and yet the camera happily decided they were all the same.

On this combined image the black is around (2,2,2), the grey is around (145,145,145) so lighter than neutral grey and the white is (230,230,230), so really a very light grey.  Comparing the white felt with a sheet of paper it is clearly on the gray side of white.

I was careful in this set of images to white balance the camera using the grey card before shooting as I wanted to reproduce the grays accurately, thus there is no colour caste in any of these images.  In reality most shots I have taken of grey scenes contain a caste driven by the colour of the ambient light.

So the lesson is, careful trusting a cameras light meter where there is limited colour variation, use a handheld meter or grey card and always shoot RAW!

Project 33

My goal in this and the previous project was to find the colours and photograph them as objectively as possible, to the extent that for many of the colours I put the camera into manual focus and deliberately threw the image heavily out of focus.  By doing this the camera would record a better averaged colour and perception of the Hue would not be influenced by knowledge of the subject.

As discussed in the text, green is easy to find, although a pure green is as rare as a pure red, yellow, or blue.  In the image below I selected as neutral colored a patch of grass as I could find.  The orange comes from a shop fronts painted surface.  In this case I was very careful to establish correct exposure as the camera automatically heavily overexposed the subject and significantly muted the fieriness of the hue.  The final hue, Violet was hardest to find, some flowers provided the nearest hue that I was able to discover (in this case I maintained focus to ensure that the green of the stems did not mix into the violet of the petals).

In this case the most accurate representation of Orange is the middle image (Where I carefully set the exposure), likewise with Green.  In the case of the Violet, the under exposure by one stop is correct.  The green as suggested is nowhere close to a neutral green, the pure spectral colour is far brighter and intense than is found in nature, or at least in nature in temperate regions.

Once again I have built a palette of what I think are pure colours, mixing is not so easy with RGB

Green is RGB = 0,255,0, Orange is RGB = 255,127,0, and finally Violet is RGB = 127,0, 255.  Admittedly, these are far to bright, mixing pixels is different from mixing light or pigments.

Once again better colour renditions came from my Autumn shots

I have to admit, I have found this exercise rather frustrating, accurate colour reproduction is a stepwise process that begins with selection, but does not end there.  The human brain is quite capable of white balancing itself.  I have experienced this when diving, if I spend too much time looking at the review screen on my camera underwater and then look away, the reef takes on a distinct red tinge for a few seconds, then my brain rebalances.  In any circumstance perception of colour is highly individual and strongly influenced by the environmental conditions prevailing.

Accurate colour management and reproduction is straightforward:
  1. White balance the camera to the light relfected by a gray card
  2. Set an incident light exposure reading and lock the camera into fully manual mode
  3. Edit photos on a colour calibrated screen
  4. Print to a colour calibrated printer

Project 32

As mentioned in the course guide, finding pure colours that correspond to the primary colours on the colour wheel is extremely difficult, and probably impossible, without seeking highly artificial circumstances in which the colour very carefully reproduced and measured using a colorimeter.  I also feel that colour is highly subjective, humans have strongly varying reception to colour, various degrees of colour blindness exist.  Even the suposedly pure blue of the sky contains a significant red and green content in the RGB model:

The sky RGB values in this image are roughly 38,39,60. Clearly Blue is the dominant component, but Red and Green are not insignificant.  To test this further I created a powerpoint slide with three blocks of colour Blue, Yellow and Red.  The Blue was created with RGB = 0,0,255, Red with RGB = 255,0,0, and finally Yellow with  RGB = 255,255,0.

From a computer monitors point of view, these are the pure colours! With a properly calibrated screen and printer I could now print these and get a reference for further tests.  However, what would be the point, pure colours such as these are the creation of a machine and not natural light.

All of this is a preamble to my set of primary colours, none of which remotely match the colours above, but to my eye at the time of creating the image were pretty close to what I would see as a base colour

In each case I have shot at a -1/2, 0, and +1/2 stop variation from the exposure suggested by the camera.  The blue is from the side of a container, the red was a tarpaulin, and the yellow is from a post box.  To improve this exercise I should have established a neutral white balance and exposure at time of shooting using a grey card.  In the images in this project and the next I have used the same white balance in Lightroom (cloudy) as all shots were taken in shade under a cloudy sky.

In the case of the blue and red the middle exposure has the best rendition of the colour I experienced at the time.  In the Yellow sample the camera has darkened the colour as it tried to push the brighter yellow towards a neutral grey.  In this case the +1/2 stop shot is the best, although I think +1, or even +3/2 would have been better.  I have done a few weddings for friends and found from experience that bright colours, especially white need to be over-exposed or heavily adjusted in Lightroom, thanks goodness for RAW.

The best primary colours I have achieved recently has been when shooting the autumn foliage, sadly I did not take equivalent over/under shots, now it is too late, the leaves have fallen: